Process for lowering the cold test of lubricating oils



J. W. WEIR ET AL.

PROCESS FOR LowERING THE COLD TEST 0F LUBRICATING oILs Sept 23 Filed June 2l. 1920 Riba INVENTOR.

f v I Patented Septg23, 1924.

UNITED A'STA JAMES W. wma AN'D WILLIAM 1. RYAN, Ja-,.or,r1LLmonE, CALIFORNIA rnocnss rca Lcwanme THE com: TEST or LUBR'ICATING ons.

Ap'pliatm ned Juncal', 1920. Serial 1ro'. 390,417.

T all lwhom. t may concemr. Y Be it known that we, JAMES W. WEIR and WILLIAM J. RYAN, Jr., citizens of the United States, both residing at lFillmore, in the county of Ventura and State of California, have invented a new and useful Process for Lowering the Cold Test of Lubricating Oils, of which the following is aspecication.

This invention relates to a vI'ocess for effecting the separation of para. wax, amorphous wax, gummy or gelatinous substances, or hydrocarbons which normally solidifyj-or become semi-solid below a temperature of ap proximately 140 F. from mineral, vegetal'nle oranimal oils, or hydrocarbons normally liquid at the same temperature.

An object of the' invention. is to lower the cold test of lubricating oils so that they will not solidify at comparatively low temperatures.

Another object of the invention is to eeet the separation expeditiously and inexpensively. 1

Another object is to provide a continuous 4process or one that is semi continuous by the admixture of a wax-adherent carrying medium with the oil tobe treated, orwith a diluted solution containing 'the-oil, at a 'ref' solid or semi solid hydrocarbons have adhered .to said medium, through afilter of any` suitable type capable of extracting or sepaf rating the wax-adherent medium and its'adhering hydrocarbons from those lhydroc'zarjbons which are liquids at the temperatures and preures under which the liquid hydrocarbons pass through the filter.

The accompanying drawing is a more or "less diagrammatic view, largely in section,

of an apparatus capable of performing the various operations incident to the process.

The apparatus illustrated in the drawing is only typical and is shown and will be described merely for the purposeof aiding in understanding the process, and it is to be understood that any other.v suitable apparatus may besubstituted for that shown and described to effect the proce. The apparatus shown in the drawing is constructed as follows: There is provided `a mixing tank 1 having in its interior a shaft 2 provided with mixing paddles 3. The shaft proj ects. through the upper end of the tank 1 and is provided on its projecting end with a pulley 4 adapted-to` be operated by being belted to any 'suitable prime mover. The paddles 3 serve to proper] stir, beat and mix the'substances dischar e into the tank. The upper end of ythe ta is provided with an inlet 59 with which communicates a receiving hopper 5 provided with a valve 6. The upper end of the tank 1 is provided with another inlet 7 with which communicates tubing 8 having a valve 9. Connected with the tube 8 is a branch tube 1.() having a valve 11. The tank 1 is providedat its lower end with a'third inlet 60 with which connects a tube 61 provided with a valve 62. The lower end of the tank 1 forms` acone 12 from which 4discharges apipe 13]. provided with a valve 14. v The pipeJl` 13 "may connected directly with the coil 15 of achiller, indicated in general by the character 16 and constructed in any suitable'manner, andthe contents ofthe pump 17 andthe pump is connected with the coil 15, so'that, if desired,` the contents of the tank 1 may be pumped through the coil 15. A l

The discharge end. of fthe coil l5 is connected by a tube 18 with -the pipe 13 andthe duced temperature and then passing the j wax-adherent medium, after the wax or other' tube 18 is provided with a valve 19. The coil 15 connects with a nozzle 20 provided with a valve 21. The nozzle 20 passes through the wall of an insulated cold chamber 22 and discharges into the tank 23 of a filter press indicated in general by the character 24. This lil-ter press may be of any known or preferred type employing lvacuum or pressure. The filtrate' discharge .pipe from the filter press 24 is indicated at 25 and is connected with a storage tank 26.

The solids or semi-solids discharge from the filter press 24 into thel trough 27 of a conveyor, the conveyor screw being indicated at 28. With the trough 27 is connected the disch-arge nozzle`29 of a heater 30 which is connected by a pipe 31 with a 4tank 32 adapted 'to holda suitable diluting` or washing liquid supplied to the tank through a tube 33 provided with a valve 34. The pipe 31 is provided with a valve 35. The heater is provided with a second disch-arge nozzle 36 having a valve 37. l

The conveyor trough 27 and the nozzle 36 both discharge into a suitable insulated Washing tank 38 provided in its!- interior with stirring paddles 39 on a shaft 4() which projects through the upper end of the wash- ,tank 1 may-'be discharged by .gravity into ing tank and which is provided with a pulley 41 whereby the shaft 40 may be connected by a belt to any suitable prime mover for operating the paddles 39. Connected with the washing tank 38 is a steam supply pipe 42 having a valve 43.A A lso connected with said tank are compressed air supply pi es 44, 63 having valves 45, 64, respective y. The washing tank 38 is provided with a heating coil 46 adapted to be supplied with steam by a pipe 47 having a valve 48. The lower end of the washlng tank 38 forms a cone 49 from which discharges a ipe 50 connected with a suitable cooler 51 tiat is rovided with a discharge nozzle 52 arranged to discharge into the tank 53 of a filter press, indicated in general by the character 54. The filter tank 54 may be of an suitable type and the filtrate dischargesl rom the filter press through a plpe 55 which empties into a 'storage tank 56.

The filter press 5,4 is arranged to discharge the solids and semi-solids therefrom into a suitable bin or hopper 57. The hopper 57 is arranged to discharge its contents into a suitable conveyor 58 which, in this instance, is of the screw type.

In practice, the process is performed with the hereinbefore described apparatus as follows:

The hydrocarbons to be treated for removal of the parain wax, amorphous wax, gummy or gelatinous substances or, in other words, those hydrocarbons which normally solidify or become semi-solid below a temperature of approximately 140 F., are admitted into a suitable mixing tank such as, for example, the tank 1 through the tube 8, the valve 9 being opened for this purpose. plied with a diluent such, for example, as naphtha., alcohol or any other liquid suitable for lowering the cold test and viscosity and decreasing the specificgravity of the hydrocarbons being treated. The diluent is mitted to the tank 1 through the tubes 10, B byopening the valve 11.

'lhen a wax-adherent carrying medium will be supplied to the tank 1 through the hopper 5, the valve.6 being opened'. to admit the medium to the tank. The carrying medium may be of any suitable character capable of permitting or inducing the adhesion of wax thereto and examples of such mediums are diatomaceous earth, fullers earth, clay, sand, saw-dust or any other comminuted solid or porous substance or any fibrous mineral, vegetable or animal substance. Diatomaceous earth, in a finely powdered condition such as that found, for example, in vCalifornia, deposits, is particularly well adapted for the purpose.

The naphtha or other diluent is added to the hydrocarbons in a liquid condition at the temperatures employed in the process.

The mixing tank 1 will also be sup-` The diluent, hydrocarbons and wax-adherent medium are thoroughly mixed in the tank 1 and the mixing may be effected in any suitable manner. One way of effecting the mixing is by operation of the paddles 3, or air is admitted to the tank through the tube 61 by opening the valve 62, or the paddles and air can both be used. The paddles and air function to agitate the various ingredients of the mixture. The ingredients are kept from settling by constantly stirring or agitating the mixture.

After mixing of the diluent, hydrocarbons and wax adherent medium is effected, the valve 14 is opened, thus allowing the mixtureI to fiow through the pipe 13 into the chilling coil 15. This may be effected by gravity or the .pump 17 may be operated to pump the mixture through the chilling coil. The mixture will be chilled in the coil 15 sufficiently to cause the amorphous wax or other hydrocarbons which areto be removed to congeal and chng to thel surfaces of the particles of diatomaceous earth or,

other wax-adherent medi-um em loyed.

The valve 21 will be opened t ius allowing the chilled mixture to discharge into the filter 24. The filter 24illustrated is of the type known as a filter press and it may be of the pressure type or the vacuum type. If the vacuum type of filter press is employed the process will be continuous, and if the pressure type of filter press is employed the process will be partially continuous. The mixture in the filter press 24 is maintained at the desired temperature because of the action of the cooling coils 65 in the cold chamber 22.

In the filter press 24 the diluent and the hydrocarbons, which are liquid at the temperature employed, are separated from the solids and semi-solids, said diluent and liquid hydrocarbons fiowing through the pipe 25 into the tank 26, the wax-"adherent medium together with the wax adhering thereto being deposited upon the filtering surfaces of the filter press and forming a cake which discharges into the conveyor trough 27. The oil received in the tank 26 is separated from the diluent alsoreceived by said tankby the well known methods of distillation and, if the oil is to be used as a lubricant, it may be reduced to any' desired consistency.

The tank 32 will be supplied with a suitable solvent or washing liquid through the pipe 33 by opening the valve 34. The solvent may be naphtha, alcohol or any other liquid capable of dissolving the wax or other congealed bydrocarbons forming the cake.

The valve 35.will be opened to allow the solvent to pass into the heater 30 which thus functions to heat the solvent. The heated solvent discharges through the tube 29 into the trough 27 and is mixed with the cake in said trough, the mixing being accomv -both the trough and said tanlrlj be admitted through the tube 63 by `openin The cake, together with whatever solvent has been admitted to the conveyor trough 27 and mixed therewith, will be transmittedby the conveyor screw 28 to the'washing' tank 38 where the washing operation is performed. To assist in the washing operation i the :paddles 39 may be operated or air may the valve 64 or the paddles and air ma bot be employed. .The cake is dissolved y the heated solvent and the dissolving action isa'ssisted by the stirring, mixing or agitation v of the cake and-solvent in the washing'tank 2o 38 The mixture thus formed -in the tank "38` includes'the amorphous wax or other hydrocarbons which were separated bythe filter 24 from the oil and diluent received by the,t

tank 26, and said mixture also includes the wax-adherent medium and the solvent, and the next operation is to separate the wax and solvent -from the wax-adherent medium and this operation will nowr be described.

The mixture flows from the tank 38 through the pipe to the cooler 51"."'where the mixture is reduced to the desired temperature, such temperature preferably being suiciently low to prevent Vaporization of the hydrocarbons.l From the cooler 51 the cooled mixture discharges through the nozzle 52 into the filter 54 which, in this instance, is of the type known as a filter'press vof either the pressure or vacuum type. This lter press 54 separates the wax-adherent medium from the liquid, the liquid being a mixture of the solvent and the amorphous wax o r other hydrocarbons which congeal or solidify at a temperature less than approximately 140 F'. The liquids iow from the 'ilter through the pipe 55 into the tank 56, and the Washing liquid or solvent is separated from the wax or other extracted hydrocarbons by any Well known methods of distillation and refining. The wax-adherent medium forms a cake in the lter press 54 and such cake is discharged into the hop. per 57 and from said ho per the wax-adherent medium discharges 1nto the conveyor 58 which conveys the wax-adherent medium to any desired place of deposit. e This wax-adherent medium may then be reemployed as before for effecting the deposition of Wax upon the surfaces thereof, which is to say, that the wax-adl1erent medium may be' again introduced tothe tank 1 through the hop# per 5 to make another'cycle... The.waxad herent medium may thus be used over and over. o

lf it be desired to temporarily discontinue operation of that portion of the apparatus to. the right of the -valve 21, said valve will be closed and the valve 19 will be opened to permit f' circulation of the cooled mixture through the chilling coil 15, pipes 18 and 13,

so that the. mixture will 4not clog this` portion` of the apparatus, as would result if such circulation were not provided for when the'valve 21 is closed.

From the fore oing it 4will be understood thatftfhe lessential operations of the rocess arethe-'mixing together of a wax-a herent medium and the hydrocarbons containing the wax which is to be removed, chilling'the mixture to congeal the wax, and then filtering the chilled .mixture tov separate the uncongealed'bydrocarbons from the waxv and l'Waxadherent medium. 'The '-other operations described are important for working theprocess on a commercial basis and have therefore been described in detail. l

It is to be understood that the term wax employed in this specification generically :defines any ofthe hydrocarbons which congeal or solidify or cease to be liquid at a tempsrature not substantially higher than 140 In practice the above described invention has beeny employed under the following conditions and with the results here stated:

By well vknown methods of distillation, under a suilicient reduced pressure to prevent a substantial cracking, crude petroleum oil producedfrom wells in Ventura County, Cali ornia, having a gravity of 319 Baume and a paraffin wax content of 6.4%, was used to obtain a lubricating oil distillate fraction, which was 32% by v-olume of the crude oil distilled. This lubricating oil distillate commonly called wan distillate, containing 20% of paraffin wax, was reduced by the Well 4known method of distillation with fire and steam to a S11/2% of bottom, which w-as equivalent to 10% of the crude petroleum oil from which it was obtained.

This reduced lubricating oil stock Wasi treated at vthe rate `of 25 pounds of 66' Baume sulfuric acid per barrel of oil, by 1 well known methods, giving a finished yield of 75% of the stock so treated, which was'equivalent to Z1/3%v of the crude vpetroleum oil from which it was obtained. The viscosity of this acid treated lubricating oil stock was 58 seconds at a temperature of 210 Fahr., Saybolt viscosimeter; the paraffin VWax content 25%, substantially all of said paratlin wax contentl being in the amorphous form.

To this' acid treated lubricating oil stock was added a petroleum oil diluent which had a gravity of 55 Baum, making a. mix of 25 parts by volume of acid treated lubricating oil .stock to 75 parts by volume of diluent. The viscosity of this mix was 31 seconds at 100 Fahr., Saybolt viscosimeter.

To this diluted acid-treated lubricating oil stock was added -one half pound of a wax adherent medium, diatomaceous earth,

per g-allon of diluted oil stock. This mix-' ture of lubricating oil' stock, diluent, and wax adherent medium was then thoroughly commingled by means of mechanical agitation and then passed under pump pressure.

through a Gray chille-r of well known type, where the temperature was reduced to 0 Fahr. At -this reduced temperature the paraffin wax content of the mixture changed from the liquid to Ithe solid and semi-solid state. and whilel lat this reduced temperature, 0 Fahr., and under a pump pressure of approximately 75 pounds gauge pressure this chilled mixture was passed into a Kellyl I cloth into a pipe which leads to the receiving tank. The filter cake containing the paraffin wax (61% of the diluted lubricating oil stock) was conveyed by means of a conveyer into a receiving tank and mixed with a sufficient amount of a hot petroleum oil distillate which dissolved the paraffin wax-content contained therein, and the dissolved paraffin wax was separated from the said petroleum oil distillate solvent and wax adherent medium by a subsequent filtration and distillation well known in the art.

The diluent and lubricating oil stock separated from the paraffin` wax and wax adherent medium was then subjected to a distillation process and the lubricatingr oil separated from the diluent. The lubricating oil thus separated from its paraffin wax content was 5.6% of. the original crude petroleum oil from which it was made, and has a viscosity of seconds at 210 Fahr. Saybolt viscosimeter. The per cent of paraffin wax separated from the lubricating stock was 1.9% of the crude petroleum oil. This example of an actual operation carried on in employment -of this invention is for illustrative purposes only and the invention is not limited thereto.

We claim:

.1. The process of lowering the cold test of lubricating oils comprising a mixing diluted lubricating oil stock with comminuted wax adherent material, passing the mixture through a. chiller to chill the mixture sufficiently to congeal its wax content, the diluted stock consisting of lubricating oil stock together with lower boiling point hydrocarbons and producing with the 'wax adherent material'a mixture pumpable at the wax' 2. The process of lowering the cold test of lubricatinr oils which consists in combining with lubricating oil stock containing Wax, a diluent and additionally adding thereto a eomminuted wax adherent medium, then chilling the mixture thus produced to congeal 'the wax upon the wax adherent medium, the diluted stock other than the wax remaining liquid and then separating the chilled associated wax and wax adherent medium fronrthe liquid mixture.

3. The process of lowering the cold test of lubricating oils by separating hydrocarbons which normally solidify or become semi-solid below a temperature of approximately 140 F., from hydrocarbons which 'remain liquid at that temperature which consists in adding a diluent and comminuted hydrocarbon adherent medium to lubricating oil stock, then chilling the mix-ture sufficiently to congeal the hydrocarbons which solidify or become semi-solid below the temperature of approximately 14:0o F., the other hydrocarbons in the mixture remaining liquid, then filtering the liquid hydrocarbons from the solidified hydrocarbons and hydrocarbon adherent medium and maintaining the mixture at the chilling temperature during the filtering operation.

4. A process of lowering the cold test of lubricating oils which consists in combining with lubricating oil stock containing wax, a wax adherent medium and a diluent, chilling the mixture thus produced to congeal the wax upon the wax adherent medium, the diluted stock other than the wax .remaining liquid and then separating the' chilled associated wax and wax adherent medium from the liquidmass.

5. A process of lowering the cold test of lubricating oils which includes lthe operations of combining with lubricating oil stock a diluent and a wax adherent medium, chilling the mixture thus produced to congeal the wax upon the wax adherent medium, the diluted stock other than the Wax reniainiug liquid, thenseparating the chilled associated wax and Wax adherent medium from'the liquid mass, then dissolving the wax that has been congealed on the wax adherent medium with a solvent and separating the wax solution from the wax adherent medium.

6. A process of lowering the cold test of lubricating oils which includes the operation of combining with lubricating oil stock, while the wax is dissolved therein, a coml 1,509,325 y l 5 minuted Wax adherent medium, chilling thel medium may be re-used in a similar cycle of mixture thus produced to congeal the wax operations. upon the wax adherent medium, the diluted Signed at Los Angeles, California this stock other than the Wax remaining liquid, 15th day of June 1920.

5 separating the chilled associated wax and v Wax adherent medium from-the liquid mass JAMES W' WEIR- then heating and dissolving with a suitable WILLIAM J' RYAN-JR solvent the chilled associated Wax, and inally l Witnesses:

separating the Wax adherent medium from GEORGE H. HILEs,

10 this solution whereby the Wax adherent L. BELLE WEAVER. 

